As shown in FIG. 1, a connecting structure for stretching and swing between a USB head and a USB body of a traditional USB head interface device is complex and has poor usability, and can only realize swing on one plane but cannot realize adjustment and use for any angle, which is very inconvenient for use of users.
Along with expansion of wireless internet technologies, network cards rise suddenly in consumer electronics products. Sockets of one computer are dense, and on one apparatus with multiple USB interfaces, interference often occurs between an external apparatus, such as a mouse, a keyboard, a headphone or the like, and an in-line network card. The body of a traditional in-line network card is longer and occupies larger space, which brings great inconvenience to users for daily use and often causes a phenomenon that the USB head of the network card is broken or that a USB cap is lost.